Indium-tin oxide (ITO) film and process for its production

• US 7,285,342 B2
• Filed: 11/11/2004
• Issued: 10/23/2007
• Est. Priority Date: 05/12/2000
• Status: Expired due to Term

• Current Assignee: Oerlikon Deutschland Holding GmbH (OC Oerlikon Corporation AG)
• Original Assignee: Unaxis Deutschland GmbH
• Inventors: Trube, Jutta, Klöppel, Andreas
• Primary Examiner(s): McNeil; Jennifer
• Assistant Examiner(s): Speer; Timothy M.
• Application Number:
  US10/986,597
• Publication Number:
  US 20050175862A1
• Time in Patent Office: 1,076 Days
• Field of Search: 428/697, 428/702, 428/689, 204/192.1, 204/192.29
• US Class Current: 428/701
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: H01L 31/022475 composed of indium tin oxide [ITO]
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: H10K 2101/00 Properties of the organic materials covered by group H10K85/00
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A process for the deposition of transparent and conductive indium-tin oxide (ITO) films with a particularly low resistance of preferably less than 200 μΩcm and a small surface roughness of preferably less than 1 nm on a substrate, wherein combined BF/DC sputtering of an indium-tin oxide (ITO) target is employed and wherein the process gas is supplemented by an argon/hydrogen mixture as reaction gas during the sputtering, as well as ITO-films with the above-named characteristics.

Claims

1. A single layer indium-tin oxide (ITO) film for use as a transparent and conductive electrode on a substrate, comprising:

a single layer ITO film wherein the single layer has both;

a) a specific resistance of less than 200 μ

Ω

cm and

b) a surface roughness of less than 1 nm.

2. An ITO film in accordance with claim 1, wherein the specific resistance ranges from 120 to 180 μ

Ω

cm.

3. A single layer indium-tin oxide (ITO) film made by the process comprising combined HF/DC sputtering of an ITO target to deposit a single layer of an ITO film onto a substrate, wherein a process gas is supplemented by an argon/hydrogen mixture as reaction gas during the sputtering and wherein the ITO film has a resistance of less than 200 μ

Ω

cm and a surface roughness of less than 1 nm.

4. An ITO film of claim 3, wherein the resistance of the film is between 120 μ

Ω

cm and 180 μ

Ω

cm.

5. An ITO film of claim 3, wherein at least 30% of total power for the HF/DC sputtering is HF power.

6. An ITO film of claim 3, wherein at least 60% of total power for the HF/DC sputtering is HF power.

7. An ITO film of claim 3, wherein HF power comprises 40% to 90% of total power for the HF/DC sputtering.

8. An ITO film of claim 3, wherein HF power comprises 60% to 80% of total power for the HF/DC sputtering.

9. An ITO film of claim 3, wherein the argon/hydrogen mixture comprises an argon:

hydrogen ratio of 80;

20.

10. An ITO film of claim 3, wherein the argon/hydrogen mixture constitutes between 0.1% and 30% of the process gas.

11. An ITO film of claim 3, wherein the argon/hydrogen mixture comprises an argon:

hydrogen ratio of 80;

20 and the argon/hydrogen mixture constitutes between 0.1% and 30% of the process gas.

12. An ITO film of claim 3, wherein the argon/hydrogen mixture comprises an argon:

hydrogen ratio of 80;

20 and the argon/hydrogen mixture constitutes between 5% and 15% of the process gas.

13. An ITO film of claim 3, wherein the argon/hydrogen mixture comprises an argon:

hydrogen ratio of 80;

20 and the argon/hydrogen mixture constitutes between 8% and 10% of the process gas.

14. An ITO film of claim 3, wherein pressure of the process gas during sputtering is between 0.5 μ

mbar and 5 μ

mbar.

15. An ITO film of claim 3, wherein pressure of the process gas during sputtering is between 1.5 μ

mbar and 3 μ

mbar.

16. An ITO film of claim 3, wherein temperature of the substrate during deposition of the ITO film does not exceed 250°

C.

17. An ITO film of claim 3, wherein temperature of the substrate during deposition of the ITO film does not exceed 200°

C.

18. An ITO film of claim 3, wherein the HF/DC sputtering is magnetron sputtering.

19. An organic LED display having a transparent and conductive electrode comprising an ITO film of claim 3.

20. A single layer indium-tin oxide (ITO) film made by the process comprising combined HF/DC sputtering of a single layer of an ITO target to deposit an ITO film onto a substrate, wherein a process gas is supplemented by an 80:

20 argon;

hydrogen reaction gas mixture during the sputtering, wherein the reaction gas mixture constitutes between 0.1% and 30% of the process gas, and wherein the ITO film has a resistance of less than 200 μ

cm and a surface roughness of less than 1 nm.

21. A single layer indium-tin oxide (ITO) film, wherein the single layer has both a specific resistance of less than 200 μ

Ω

cm and a surface roughness of less than 1 nm, made by the process comprising combined HF/DC sputtering of a single layer of an ITO target to deposit an ITO film onto a substrate, wherein a process gas, having a pressure of between 0.5 μ

mbar and 5 μ

mbar, is supplemented by an argon/hydrogen mixture as reaction gas during the sputtering and wherein the substrate temperature does not exceed 250°

C. during the deposition of the ITO film.